Gas turbine engines may be used in aircraft, power plants, tanks, etc. to power various components thereof. A typical gas turbine engine includes, for example, an intake section, a compressor section, a combustor section, and a turbine section, and each section may include one or more engine components mounted to a common shaft. The gas turbine engine may also include an exhaust section that is located downstream from the turbine section.
Generally, the intake section induces air from the surrounding environment into the engine and accelerates the air toward the compressor section. The compressor section, which may include one or more compressors, raises the pressure of the air it receives from the intake section to a relatively high level. The compressed air then enters the combustor section, where a ring of fuel nozzles injects a steady stream of fuel into a combustion chamber. The injected fuel is ignited to produce high-energy compressed air. The air then flows into and through the turbine section to impinge upon turbine blades therein to rotate the shaft. The shaft may be coupled to a propeller or other component, and may provide energy for propulsion thereof. The air exiting the turbine section may be exhausted from the engine via the exhaust section. The air passes through an engine flowpath of the gas turbine engine.
Under certain operating conditions, the air passing through the gas turbine engine along the engine flowpath may include dirt, dust, sand, and other solid particles (hereinafter “particulate matter”) suspended therein (the air including the particulate matter is hereinafter referred to as a “primary gas flow stream”). At least a portion of the particulate matter may fall on the inside engine component surfaces and settle thereon, with no exit path, thereby trapping the particulate matter inside the gas turbine engine. Particulate matter that collects inside the gas turbine engine may cause diminished performance and accelerated wear on the engine components. For example, particulate matter may cause erosion in the compressors. The particulate matter may get heated in the combustor section, which may cause clogging or plugging of critical orifices and/or glassing of combustor surfaces. As there are spaces in the gas turbine engine that can be narrow, any particulate matter build up may restrict airflow, including cooling airflow. In addition, as operating hours accumulate on gas turbine engines, particulate matter buildup may worsen until a mandatory engine teardown is required. Gas turbine engines operating in dirty, dusty, or sandy areas are especially prone to particulate matter buildup.
Some gas turbine engines have external and/or internal inertial particle separators or fixed barrier particle filtration systems that reduce the amount of larger particulate matter entering or being trapped inside the engine. However, these systems do not entirely prevent particulate matter from entering the engine. In addition, such systems may be heavy, detrimentally affect engine performance, require increased maintenance, and are unable to operate in certain conditions. Furthermore, filters in fixed barrier particle filtration systems are themselves susceptible to plugging with particulate matter.
Accordingly, it is desirable to provide gas turbine engines and systems and methods for removing particulate matter therefrom during operation. It is also desirable to remove particulate matter from inside the engine, without additional weight, without detrimentally affecting engine performance, without increased maintenance, and with the ability to operate in most conditions. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.